Poromeric plastic coated fabrics were known in the prior art. Such materials as "Corfam" of duPont, "Aztran" of B. F. Goodrich, and "Genaire" of General Tire Company have been or were on the market for several years, each with dubious success and ultimate failure. The plastic coated fabrics may be made in a variety of ways, e.g., with polyvinyl chloride, polyurethane and the like polymers, and the microporosity being provided with various means including single microspheres as disclosed in my prior U.S. Pat. Nos. 3,353,981 and 3,718,561, as well as in my simultaneously filed U.S. Pat. application Ser. No. 933,543, filed Aug. 14, 1978. A disclosure of the invention of the present application was made in summary form in Disclosure Document No. 071468 dated May 23, 1978.
The use of single microspheres, in production, sometimes tends to give erratic results, and an end product which lacks uniformity throughout its area as regards microporosity. It also may lack, unpredictably, cosmetic elegance due to the tendency of single microspheres to move towards each other and cluster in random fashion in the coating material while the coating material is still fluid.